Viessmann Vitotwin 300-W Installation And Service Instructions For Contractors page 147

Repairs
(cont.)
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
Sensor type: NTC 10 kΩ
2. Test the resistance of the flow tem-
perature sensor at the disconnected
plug and compare it with the curve.
3. Where actual values deviate severely
from the curve values, disconnect the
wires at the sensor and repeat test on
the sensor itself.
4. Depending on the result, replace the
lead or the flow temperature sensor.
Troubleshooting
147